Medical and pharmaceutical devices are frequently manufactured from biodegradable or water-soluble polymers. Biodegradable polymers contain biodegradable linkages that readily break down into small segments when exposed to moist body tissue or physiological enzymes. The segments are either absorbed by the body or passed by the body. More particularly, the biodegraded segments do not elicit permanent chronic foreign body reaction, because they are absorbed by the body or passed from the body such that no permanent trace or residual amount of the segment is retained by the body. Water-soluble polymers contain linkages that are dissolved in the body fluids and are subsequently passed by the body.
Examples of medical devices, which can be manufactured from biodegradable or water-soluble polymers, include sutures, suture anchors, screws and pins for fastening or securing tissues after a surgical procedure. Other examples include topical adhesives for securing tissue and internal sealants to suppress the leakage of blood or other fluids from tissue. Biodegradable or water-soluble polymers are also used in the manufacture of pharmaceuticals. Often, the polymers are used as carriers for the active pharmaceutical agent. In general, however, for both of these applications, properties such as biocompatibility, strength, proper flexibility, wettability, durability, and ease of delivery need to be optimized.
Dithiocarbonate polymers have been described in U.S. Pat. No. 6,372,871 B1. In this patent, dithiocarbonate is defined as a 5-membered cyclic dithiocarbonate. For example, dithiocarbonate-containing macromers have been shown to readily react with diamines to form polythiourethanes. These polymers can be utilized for applications such as wire coatings and inks where chemical and water resistance are important physical properties. Unfortunately, these polymers do not have hydrolyzable linkages that would make them suitable for medical or pharmaceutical applications.
Therefore, there is a desire for a new class of biodegradable or water-soluble dithiocarbonate-containing macromers and polymers derived therefrom that could be used for medical and pharmaceutical applications. The polymers ideally could be prepared into preformed devices or prepared in situ by delivering the reactants to a body cavity in a fluid form.